1. Field of the Invention
This invention relates to wire and cable. In one aspect the invention relates to wire and cable insulation and protective jackets while in another aspect, the invention relates to wire and cable insulation and protective jackets comprising a flame retardant (FR) free of halogen. In yet another aspect the invention relates to such wire and cable insulation and protective jackets in which the flame retardant comprises a hybrid polyphosphate of ammonium, melamine, piperazine and triazine polymer.
2. Description of the Related Art
Thermoplastic polyurethane (TPU)-based halogen free flame retardant (HFFR) product packages are usually employed for wire insulation/cable jackets for personal electronics. These are used as a replacement for halogen containing products. Advantages of this type of product are superior mechanical properties and flexibility. Additionally, TPU-based FR polymers fulfill the heat deformation testing (UL-1581) requirements at 150° C., which is particularly important for some applications and, generally, can not be achieved by using uncrosslinked polyolefin as the polymer matrix. However, the main disadvantages for TPU-based FR compositions are insulation resistance (IR) failure, poor smoke density, high material density and high cost of TPU. Replacing TPU with polyolefins can potentially solve these. However, polyolefins or polyolefin elastomer-based HFFR usually suffer from a dramatic drop of heat deformation properties due to a lower melting temperature relative to TPU, especially at a high temperature (e.g., 150° C.). In addition, the use of polyolefin components can decrease the overall FR performance because of their hydrocarbon structure.
As such, achieving excellent flame retardancy and balanced mechanical properties is difficult for polyolefin-based HFFR. A solution to this problem remains of continuing interest to the wire and cable industry.